Dovetailing-machine.



Patented Mar. I2, l9l0l. J E. ERICKSON. DOVETA'ILING MACHINE.

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DUVETAILING MACHINE.

(A lication filed Jul 24, 1899.)

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No. 669,686. I Patented Mar; l2, l90l. J. E. ERICKSDN.

DOVETAILING MACHINE.

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ATENT FFICE.

JOHN E. ERIOKSON, OF ST. PAUL, MINNESOTA.

DOVETAlLlNG-MACHINE.

SPECIFICATION forming part of Letters Patent No. 669,686, dated March12, 1901.

Application filed. July 24, 1899. serial No. 724,914. No model.)

citizen of the United States, residing at St.

Paul, in the county of Ramsey and State of Minnesota, have inventedcertain new and useful Improvements in Dovetailing- Machines, of whichthe following is a specifica tion.

My invention relates to the type of dovetailing-machines illustrated inPatent No.

535,492, issued March 12, 1895, to John Leonartson and myself, in whichthe dovetails or mortises with receding sides are formed in the ends ofboards carried on a reciprocating table which cooperates with two setsof cutters of successively-increasing diameters. In the machine of thepatent referred to the cutting of mortises was done only during theupward movement of the reciprocating table, the driving-crank making acomplete revolution before stopping.

It is one of the objects of the present improvement to so organize theoperating mechanisms that they will stop automatically at eachhalf-throw of the crank, and thus enable cutting to be done at eachreciprocation of the table.

A further object of the improvements is to provide devices operatingautomatically both to clamp the boards in place on the table during thecutting operation and release them upon completion of the cutting.

Other improvements relate to convenient means for adjustment of partsfor holding boards of different thicknesses, means for adjusting theboard-guides relative to the saws, and other details of structure, allof which improvements tend to greatly increase the capacit) of themachine for turning out finished Work.

As the purpose of the machine is to prepare boards for making boxes, andespecially to enable low-grade lumber to be used for packing-boxes andother cheap boxes, the importance of such improvements as facilitate thework, increase the output, and better adapt the machine to successfullyoperate upon the cheaper grades of material is apparent.

The improvements are illustrated in the accompanyin g drawings, inwhich-- Figure 1 is a side elevation of the improveddovetailing-machine; Fig. 2, an elevation of the end of the machine atwhich the dovetail mortises are out; Fig. 3, an elevation of the tableshown in Fig. 2 and connections, showing the positions of parts whenboards may be inserted or removed. Fig. 4 is a plan view showing inoutline the general arrangement of the mechanism for reciprocating thetable, and Figs. 5, 6, 7, and 8 show details of devices hereinafter setforth.

In the drawings, 1 designates the machineframe, 2 the maindriving-shaft, and 3 the pulley thereon connected. with a source ofpower for operating the reciprocating table. The saw-arbors 4 and 5 arerotated by belts 6 and 7 on pulleys 8 and 9, connected with overheadshafting. (Not shown.) The saws 10 are circular and ofsuccessively-increasing diameters, the series forming a contour like thefrustum of a cone. The several saws of the series may be separated bywashers and connected in any well-known manner. These saws have theiredges beveled to a common plane and are placed in such positionsrelative to each other and to the bed that they may cut dovetailmortises by two successive cuts, as set forth in the patent referred to.

For operating the reciprocating table 11 there is provided a centralshaft 12, carrying on its outer end a crank-disk 13, connected by apitman 14 to the table, and on the inner end of the shaft is a beveledgear 15, and in mesh with it is a beveled pinion 16 on a shaft 17, thatextends laterally to the outside of the frame and there carries agear-Wheel 18. In mesh with the latter gear is a pinion 19 on a shaft20, which carries also a friction-wheel 21, the shaft having suitablebearings on the base member of the machine-frame. Thus the rotation ofthe friction-wheel 21 will cause the rotation of the shafting andgearing just described, and thereby operate the pitman 14 to reciprocatethe table.

For engaging the friction-wheel 21 at intervals of time to revolve it afriction-Wheel 22 is provided on a shaft 23, that carries a pulley 24,which is belted to a pulley on the main driving-shaft 2, whereby theshaft 23 and the friction-wheel it carries are kept in constantrotation. The shaft 23 is mounted on the angular arm of a lever-frame25, that is pivoted at 26 to a portion of the machine-frame and extendsdownward near the face of the brake.

friction-wheel 21 to a point at the side of the base of themachine-frame. On the side of the lever 25 adjacent the friction-wheel21 is formed or secured a brake-shoe 27 for engaging that wheel to stopits revolution. A spring 28, suitably arranged and secured at the sideof the frame 1, normally exerts tension against the lower portion of thelever and presses the brake against the frictionwheel 21. Movement ofthis portion of the lever in a direction away from the wheel serves tofree the brake and at the same time, by reason of the angularity of thelever and its pivotal connection with a fixed object, swings the shaftof the friction-wheel 22 downward and brings the two friction-wheels incon tact, and thus the gearing for producing reciprocation of the tableis set in motion.

The lower end of the lever 25 is provided with a lug or catch '29 forengaging a notch 30 in a horizontal bar 31, that extends to the end ofthe machine and is pivoted to an arm 32 on a rocking rod 33, mountedtransversely in the lower portion of the machine-frame. To this rod isattached a foot-lever 34 in con' venient position to be operated by aworkman at the end of the machine. Pressure on the foot-lever serves toactuate the bar 31 lengthwise toward the operator and by engagement ofthe notch 30 in the bar with the lug 29 on the lever 25 turns the latteron this pivot sufficiently to cause contact of the friction-wheels. Itisobvious that so longasthe friction-wheels are in contactthe tablereciprocations would continue; but stopping devices operatingautomatically at suitable intervals are provided to prevent suchcontinuous reciprocatory movements.

On the shaft 12 is a disk 35,having at two diametrically opposite pointsprojections 36 for engaging a lever 37 to depress it whenever theprojections come in contact'with it. The lever is fulcrumed at 38 to theframe 1, and its outer arm extends beneath the longitudinal bar 31 andin position to lift it when the inner end of the lever is depressed bythe projections on the disk This lifting of the bar 31 frees its notch30 from the catch 29 on the friction and brake lever, and thus permitsthe spring 28 to exert its force against the lever to free the frictionand apply the As the cam projections 36 are at opposite sides of thedisk, it is apparent that the operation of the mechanism they controlwill continue only during a half-revolution of the disk and that thesucceeding cam engagement will depress the engaged lever, and therebyactuate the brake to stop further movement. To renew the operation, thefootlever must be released and returned to its elevated position, whichmay be done by a spring (not shown) connected in any wellknown way. Whenso raised, the bar 31 is again in proper position to engage the catch inthe friction-carrying lever 25 upon depression of the foot-lever.

The reciprocating table 11 is supported by a bracket-frame 39,havingloose sleeves 40 on vertical guide-rods 41, that extend from the bottomto the top of the frame 1, and being connected by the pitman 14 to thecrankdisk 13 on the shaft 12 a throw of the crank will reciprocate thetable upward on the rods 41 from the position shown in Figs. 1 and 2 toa point above the saws, as shown in Fig.

3, where it will be stopped by the brake by reason of the operation of acam 36 on the brake connections. After a release of the foot-lever andsubsequent pressure upon it the renewal of the pitman movement willretract the table to its lower position, where it will be again arrestedin the same manner.

The boards to be out can be placed in proper position on the table bymeans of a guide 42, that prevents lateral movementand which isadjustable laterally on the table by screws 43, that pass through slotsin its base and engage the table, and other guides 44 atri'ght angles tothe former and adjacent to thesaws, which limit inward movement of theboards. The latter guides are upward-tapering projections on bars 45 andare of proper size and suitably spaced to pass freely through theinterstices between the saws. These'bars are of T shape incross-section, Fig. 7, and are held together in a series by intermediateupper flat strips 46 and lower strips 47, the latter having grooves 48along their'lower edges, in which the lateral flanges 49 of the bars 45are slidab'le lengthwise, and these strips being clamped together bybolts 50 provide a bed for the boards, as well'as furnish ways for thelengthwise adjustment of the board-guide bars 45. The series of bars andstrips are placed in a frame 51. The outei'eud of each of the bars 45 isadjustably secured by asetscrew 52 to a movable cross-piece 53. Thuseach guide-bar by freeing its set-screw may be independently removed oradjusted, and the series may be adjusted lengthwise in unison bymovement of the piece 53. The lat ter adjustment is made by a screwengaging the frame 51 and bar 53 and operated by a nut or wheel 54.The'inner ends of the strips 46 are cut away, as shown in Fig. 6, topro- 'vide projections 55, corresponding with the tongues or projectionsremaining on the boards when the dovetails are formed, and

such projections-serve as supports for the edge of the board while it isbeing cut to prevent'p'ortions from being broken or torn off by thesaws. The adjustable table-section thus built up and its frame 51 areplaced in a corresponding recess 56 in the table-bed 11. Boards are heldin place on the table by a clamping-bar 57, suspended by screws 58 fromthe cross-piece of a clamp-frame 59 above the table. Ways 60 areprovided to guide the ends of the bar, so that its position relative tothe table can be adjusted as desired by turning the screws 58 toaccommodate for boards of different thickness. From the undersides ofthis frame rods 61 extend downward through openings-in the tableand'carry table will descend to the limit allowed by the throw of thepitman 14, and so the space between the clamp-bar 57 and the table willbe widened to release the board for removal. Upon the upwardreciprocation similar stops near the top of the frame serve to arrestthe movement of the outer ends of levers 66, the inner ends of which arepivoted at 67 to the frame 59 and are intermediately fulcrumed on lugs68, provided on the table. The obvious effect of this will be theseparation of the table and clamp in the same manner as when theclamp-frame itself engages the lower stops in its downward movement. Thestops 64 and 65 are adjustable upward and downward to regulate theextent of separation of the clamp and table as desired by turning thenuts 69.

To cut dovetail mortises, a board having been placed on the table with alateral edge against the guide 42 and the inner edge against the guides44, the clamp-bar 57 being at the time in its elevated position and thetable at one or the other of its extremes of movement, a depression ofthe foot-lever 34 will free the brake and bring the frictionpulleys incontact and start rotation of the shaft 12. The first operative effectof such rotation is to start the table in its reciprocatory movements,the immediate result of which is to release the clamp-frame from thestops 64 or 65 and permit the clamp-bar to descend to the board and holdit in place. As the table approaches the limit of its reciprocation thestops 64 or 65 are again engaged and the clamp-bar lifted, andcoincidently one of the cams 36 depresses the lever 37, and the movementof the latter releases the foot-lever connection with the brake-leverand permits the brake to be applied to the friction-wheel to stop theoperating machin ery and hold it in place for the removal of the board.

Having described my invention, what I claim is- 1. Inadovetailing-machine, aseries of saws mounted on stationary supports, areciprocating table provided with a central recess; a supplemental tableseated in such recess and comprising a series of T-shaped bars havingupturned ends between the saws to serve as board-guides, and a series ofintermediate strips having projections extending between the saws tosupport and protect the tenons; and means for adjusting said bars andstrips collectively or separately toward or away from the saws,substantially as set forth.

2. In a dovetailing-machine, the combination with a series of sawsmounted on stationary supports, and a reciprocating work-table; of apitman and crank for reciprocating said table; gearing, including anidle frictionwheel, for intermittently rotating the crank; a drivingfriction-wheel, a brake, and a rocking carrier therefor arranged toapply them alternately to the idle friction-wheel; an operating-leverand connections for engaging the carrier at will to bring thefriction-wheels to con tact; a tripping-lever for automaticallyreleasing the connections to allow the carrier to rock in oppositedirection to apply the brake; and a cam operated by the drivinggear toactuate the tripping-lever .at each half-revolution of the crank,substantially as set forth.

3. In a dovetailing-machine, the combination with a series of sawsmounted on stationarysupports, and a reciprocating work-table; of apitman and crank for reciprocating said table; gearing, including anidle frictionwheel, for intermittently rotating the crank; a drivingfriction-wheel, a brake, and a rocking carrier therefor arranged toapply them alternately to the idle friction-wheel; an operating-leverand connections for engaging the carrier at will to bring thefriction-wheels to contact; a spring for rocking the carrier in oppositedirection to apply the brake; a tripping-lever for automaticallyreleasing said connections to permit the spring to so operate; and a camoperated by the driving-gear to actuate the tripping-lever at eachhalfrevolution of the crank, substantially as set forth.

4. In a dovetailing-machine, the combination with a series of sawsmounted on stationary supports, and a reciprocating worktable; of aclamp-carrying frame loosely mounted on the table; levers pivoted tosaid frame, fulcru ms therefor provided on the table, and stops on themachine-frame for engaging the free ends of the levers to lift theclamp-frame as the table nears the end of a reciprocation; a pitman andcrank for reciprocating said table; gearing, including an idlefrictionwheel, for intermittently rotating the crank; a drivingfriction-wheel, a brake, and a rocking carrier therefor arranged toapply them alternately to the idle friction-wheel; an operating-leverand connections for engaging the carrier at will to bring thefriction-wheels to contact; a tripping-lever for automatically releasingthe connections to allow the carrier to rock in opposite direction toapply the brake; and a cam operated by the drivinggear to actuate thetripping-lever at each half-revolution of the crank, substantially asset forth.

In testimony whereof I have hereunto set my hand this 14th day of July,1899.

JOHN E. ERICKSON.

In presence of- M. F. HARRISON, P. H. GUNGKEL.

